: something that yields knowledge or understanding <the great book of nature><her face was an open book>

4

a (1): the total available knowledge and experience that can be brought to bear on a task or problem <tried every trick in the book>(2): inside information or analysis <the book on him is that he can't hit a curveball>

b: the standards or authority relevant in a situation <run by the book>

5

a: all the charges that can be made against an accused person <threw the book at him>

b: a position from which one must answer for certain acts :account<bring criminals to book>